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Architecture and Instruction Set of the C 6x Processor
- Architecture and instruction set of the TMS320C6x processor
- Addressing modes
- Assembler directives
- Linear assembler
- Programming examples using C, assembly, and linear assembly code
3.1 INTRODUCTION
Texas Instruments introduced the first-generation TMS32010 DSP in 1982, the TMS320C25 in 1986 [1], and the TMS320C50 in 1991. Several versions of each of these processors—C1x, C2x, and C5x—are available with different features, such as faster execution speed. These 16-bit processors are all fixed-point processors and are code compatible.
In a von Neumann architecture, program instructions and data are stored in a single memory space. A processor with a von Neumann architecture can make a read or a write to memory during each instruction cycle. Typical DSP applications require several accesses to memory within one instruction cycle. The fixed-point processors C1x, C2x, and C5x are based on a modified Harvard architecture with separate memory spaces for data and instructions that allow concurrent accesses.
Quantization error or round-off noise from an ADC is a concern with a fixed -point processor. An ADC uses only a best-estimate digital value to represent an input. For example, consider an ADC with a word length of 8 bits and an input range of ± 1.5 V. The steps represented by the ADC are: input range/28 = 3/256 = 11.72 mV. This produces errors that can be up to ±(11.72 mV)/2 = ±5.86 mV. Only a best estimate can be used by the ADC ...
